Technical Field
Exemplary aspects of the present disclosure relate to a belt device and an image forming apparatus incorporating the belt device.
Related Art
Image forming apparatuses include a belt device such as a transfer unit as a transfer member and a conveyance unit as a conveyance member. The belt device includes an endless belt member looped around a plurality of supporting members such as rollers. Such a belt device may include a tape-like detected unit to be read by an optical detector so that a conveyance speed of the belt member is controlled. The detected unit is attached on at least one side of the belt member in a belt width direction perpendicular to a belt movement direction and across a longitudinal direction (a length direction) of the belt member. The tape-like detected unit is also called a scale tape, and has slits or roughness. The detected unit reflects detection light emitted from the optical detector, so that the optical detector receives the reflected light from the detected unit to detect the slits or roughness of the detected unit.